Once, there was nothing. Nothing was black, and nothing was white, for nothing was anything and everything. Suddenly, there was a spark within nothing. A white blob appeared, forging itself into an oval. This oval had a cracked in it, and out came the Original One. The Original One had no physical form, so he created himself one. There was just the Original One, and nothing. The Original One looked at nothing, and thought about making it better, giving it identity and purpose, just like him. The Original One was all-powerful, but could not manage existence by himself, so he created his sons.
The Original One created the Master of Space first, Palkia. Palkia's powers gave the Original one definitive physical features.
Secondly was the Being of Time, Dialga. Dialga's powers gave the Original one knowledge who was the eldest brother.
Lastly was the Guardian of Antimatter, the Forbidden One. The Forbidden One gave the Original one balance with his dark and light sides.
The Forbidden One was the youngest of the brothers, but also the closest in character to the Original one, as they both carried extreme power, but the son was the shadow of his father. He caused chaos where chaos was not needed, and the Original One persisted that his son could control himself, but he was horribly wrong. Eventually, the Original One could not let his youngest son roam free, so he banished him to a new dimension, which the Forbidden One manipulated into a suitable home, creating the Distortion World.
The Forbidden One's banishment emotionally scarred the entire family, especially Dialga. Dialga was very careful and close to his younger brother because his father was a very busy being and Palkia was short tempered. Dialga asked Palkia for guidance, hoping Palkia's fuse would not blow. When it did, the first sibling rivalry was born.
The Original One was forced to create a wall to separate his remaining two children to stop their own destruction and his own. Dialga nor Palkia would forget the original spark that ended their brotherly connection, making the wall extremely important.
Fortunately, the Original One's dark past was behind him, for the era of creation was only beginning.